My hot air panel project
 

This is a project I started collecting materials for in the fall. It is based off this design.atlanticenergy.ca > projects > Wayne Langille - Solar Air Collectors
I'm doing a much much lower budget version of it though. I picked this project after researching many DIY heaters because of it's seemingly proven performance. Looks like quite a bit of R&D went into the design and I wanted to be as successful as possible the first try.

The project sort of hinged on my ability to source cheap polycarbonate panels. I found $20 clear corrugated 2'x8' sheets on-line and my local hdw store said they could get them since it was thru thier parent company. I was excited, so while waiting for the polycarb to come in, I bought whatever else I needed. A few days later I checked in with the guy at the hdw store. He said he messed up and they can only get a minimum of 10 panels and 100 end seals :mad::confused:. NOT cool, I only needed 2 panels and 4 end seals.

So since then I put the project on hold while I finished my PV array and sat thru the coldest winter since I moved into this house. Now it's time I started looking for a suitable glazing. Many of the home improvement stores can special order only in wierd sizes at high cost. I need to find a cheap local source of either tempered glass or polycarb (not acrylic) because they have to endure high levels of heat.

I have also had a chance to observe the sun on the south side of my house where I plan to mount the heater. It looks like I will have some shading problems part of the day from a small deciduous tree and my old mesh sattelite dish. The tree is still holding most of it's dead leaves even now in march! If it would drop them like a normal tree, it wouldn't be too bad because it's small. The dish can come down and maybe even the tree. I'd hate to cut a tree, but it will probably come back. The rabbits killed it one year and it shot up suckers that I thinned to one good shoot. Now it's probably bigger than it would have been.

Very cool. I've been wanting to do this with my garage for... well since before I had a garage! I'm really looking forward to seeing what happens.

A tip I got from another site was to try your local greenhouse supply place. They should carry these sorts of things.

Have you tried any local window repair or sign shops? They might be able to bundle your order in with their regular order.

FYI here is another commercial design for a solar hot air system - AAA Template. There may be some good ideas in this design that you could use.

FWIW,
Tim

Good ideas guys . I'll have to look and see what greenhouse places there are near me. I haven't tried a sign shop yet either.

Here's a cheaper version that uses beer cans.
Beer Can Solar HeaterBeer Can Solar

Just remember to start your project with empty beer cans.

I just was given 2 framed panels of tempered glass. They are about 32" by 67". I'll have to do some figuring to see if I can work them into my design.

I looked at many designs including a 32 ft^2 active beer/pop can panel, but decided it wasn't enough cheaper to merit all the extra work cleaning, cutting, and sealing the cans together. In fact, it could be more expensive. I live in Michigan where drink cans have a 10 cent deposit, so getting 300 some cans isn't exactly the cheapest way to make an aluminum absorber, especially since we don't drink pop or beer in my house :).

Good reason. However, I know a coworker of mine gathers cans from the local bar. I'm not sure how he worked it out. We don't have the deposit here, but he turns them in for scrap money. Perhaps talk to the owner and see if he would let you have X amount of cans?

it looks like the free glass should work out OK for my plan. It will be around 30 sqft instead of 32, and the shape will be closer to square so the 8ft ducts will have to be shortened. I'll have to see how well the glass cleans up and do some more calculations.

I've been slowly cutting the materials to size for this project. I came up with a cookie cutter way of cutting all the holes in the manifolds where the absorber tubes connect. I found a metal can of the right diameter and sawed the end off so I can twist it down thru the foam board and remove a plug. It works fairly well. I have to use a blade to finish the cut on the foil on the other side. Here are some practice cuts.Attachment 151

And the tube fits well.Attachment 152

I got a little more done over the weekend. I need to finish it to make room for my saturn sc2 project. I don't know if I will get time to do a wind power project for a while :rolleyes:. I'm making sure I finish this solar panel before getting too involved with the car. The panel is farther along than the picture shows. I have almost half of the tubes stretched and cut to length with some paint on them. The side insulation is installed too.

here are the 2 glass panels I'm planning to use (not the smaller shower door). Also the completed tube manifold pieces.

Any updates on this project? I'm pretty anxious to see how this all works out! :)

I haven't been getting much done on it. I did move it to a more convienient spot. I have all the tubes roughly cut to length and painted. I think the thing that's slowing me down is the manifold front metal. I bought a coil of roof flashing that is wide enough to use, I just don't know how I want to attach it yet. I also cut the 2 tube manifold pieces in half lengthwise to make it easier to set the tubes into place on assembly. It's hard to get motivated on a heating project when it's warm outside.

I should just get it done, summer sun will help me test it.

Here's an overly compressed picture of some progress I made on the panel.
Here I'm basically dry fitting all the parts ignore the baffle placement in the manifolds. I plan to spray more paint on some of the tubes. I need to do some testing after I install the manifold front covers and hold the glass down to the front. I will be deciding where to put the inlet and outlet as well as how many tubes to run in a parallel circuit by moving the baffles around in the manifolds. I ended up buying a 12ft piece of aluminum material that is flat to use for the manifold front covers. It should be alote easier to install than coiled flashing.

Wooo, its coming together! :) Still anxious to see how this works. What are the dimensions of the box?

it's about 65" x 67"

I will finish this someday :o.

It's pretty close to done I just need to seal it up enough for testing and get the glass retained. During testing, I will decide on a fan system and thermal controls. After that I need to decide real hard about drilling a couple big holes thru the shell of my house :eek:. I think that has been my biggest hang-up, besides having too many other things going on. I may end up using a couple of windows for the intake and exhaust.

I used a Mother Earth News article to design and build a solar air heater at my house. It took me over a year, due to having too many projects at once. Plus, I over-engineered it to death. I stuck it in the window (~45 degrees outside) and in about 30 minutes it was putting out very low flow, but 105 degree air. Decided it needed a solar powered fan. Didn't buy the fan. Didn't cover the glass when summer came. Did look at melted solar air heater in mid-summer.

You might consider having a way to cover it in the hotter months, I know I wish I'd considered that. :o

Very good point.

I'm hoping mine will be fairly safe in the summer since it will be vertical and kinda tucked under a south facing overhang. I'll have to look at that part of my house and see how the sun hits it thru summer.